Clockwise from left: Reeva Steenkamp; Oscar Pistorius in court; Amee Pistorius and Carl Pistorius, sister and brother of South African of Oscar Pistorius sit in the gallery of Pretoria magistrates court EPA

The case against Oscar Pistorius has been left in the balance after the Paralympian’s defence team cast serious doubts over police work at the scene of Reeva Steenkamp’s death. One week after the world awoke to the news that South Africa’s most recognisable sportsman had been arrested and that his girlfriend had been killed, there is now a real possibility that he will be released on bail to await his trial.

The Pistorius defence team has already made overtures to the director of South Africa’s National Prosecutorial Authority about throwing out the charges. This raises the possibility of the country’s most high-profile case in recent memory following the “Zuma route” – so named after the technicality by which President Jacob Zuma’s persistent corruption charges were dismissed.

Another day of intense courtroom drama in Pretoria had begun confidently for the prosecution as investigating officer Hilton Botha, the first policeman to arrive at Mr Pistorius’s home after the killing, explained that what he found could in “no way” have been an accident. Ms Steenkamp was already dead when the detective reached Mr Pistorius’s home. She was dressed in shorts and a vest and wrapped in towels with gunshot wounds in her hip, her head and her arm.

With a floorplan of the upper storey of the athlete’s luxury home projected on to the wall of Court C, Mr Botha said that he had been persuaded by ballistics experts that Mr Pistorius had chased her into the bathroom and moved close to the door of the toilet cubicle before shooting four shots, three of which hit Ms Steenkamp. The prosecution then asked the court why had she locked herself in the bathroom if she did not feel threatened.

The notion of the runner mistaking his girlfriend’s late-night trip to the toilet for an intruder was rejected as Mr Botha told the court that two different neighbours had reported “non-stop” shouting from the house. One witness reported hearing gunshots, a woman screaming and then more gunshots. The detective described four phones recovered from the scene –two iPhones and two BlackBerries – none of which had been used to contact the police or paramedics, as the defence had claimed. The prosecution also stressed that the height and angle of the bullet holes in the bathroom door suggested they had been fired by the athlete while wearing his prosthetic legs. In Mr Pistorius’s statement on Tuesday, he claimed he was moving around his house on his stumps.

But the most acute tension came when the stocky policeman – who was speaking in English, his second language, and struggled to make himself heard in the overcrowded courtroom – described other items discovered at Mr Pistorius’s home. There would be additional charges, he said, after a safe was found to contain unlicensed heavy-calibre ammunition. He also stated that he considered the Paralympic champion to be a “flight risk” after documents relating to overseas bank accounts were found, and mentioned Mr Pistorius’s ownership of a house in Italy.

There was audible surprise when, at the prompting of prosecutor Gerrie Nel, the detective suggested that “bottles of steroids and needles” had been found. He quickly corrected himself to say the bottles contained “testosterone”, although it would later emerge that this claim was incorrect. Almost as soon as the tall figure of Barry Roux began to question the experienced detective, the tone changed decisively. Mr Botha’s occasional stumbles became outright confusion under forensic cross-examination. The policeman was forced to admit that he was unsure of the labelling on the bottles, which the defence maintained were in fact an unrestricted homeopathic supplement that shares nothing but its first two syllables with the steroid. It then emerged that Mr Botha’s claim about the Italian house was based on hearsay. He was chided gently by Mr Roux after admitting that he had tramped through the crime scene without using protective footgear. The issue of the missing phone calls was cleared up when the defence said they were in possession of a fifth phone that had been used. The assertion that Mr Pistorius must have been standing close to the bathroom door when he fired his 9mm pistol was also countered with the help of a pointer which showed that he could have shot – as he claims – from the entrance to the bathroom. The wounds suffered by Ms Steenkamp were consistent with that assertion.

Equally damaging was Mr Botha’s admission that the witnesses who reported hearing shots and voices had been more than half a kilometre from Mr Pistorius’s house. Mr Botha was accused of “disregarding any evidence” which was not consistent with his preconceived notion that a murder had taken place. After more than an hour of hectoring, the detective, with 26 years of experience, was asked by Mr Roux whether the state’s evidence was “inconsistent” with the account given by Mr Pistorius the previous day. A forlorn Mr Botha replied “no”.

During these exchanges the hunched, sobbing Mr Pistorius of the first day was replaced by an upright, alert observer. “At last the truth is coming out,” said his uncle Arnold.

By the time Mr Botha left, he admitted he was no longer confident that the accused athlete would be denied bail, despite the seriousness of the charges against him. The prosecution team who had remained silent for much of the final hour admitted privately that it had been a “damaging” day. Today both sides must make their concluding arguments. The prosecutor does so knowing that should Mr Pistorius be bailed, he may never be back in the dock again.

Waiting game: South Africa's bail rules

The bail hearings for Oscar Pistorius are not intended to determine guilt or innocence, despite the detailed claims and counterclaims put forward at the Pretoria Magistrates Court this week about the events surrounding the death of Reeva Steenkamp.

As South African law scholar Pierre de Vos explains, bail is not easily denied in South Africa. Under South African law, every person arrested has the right “to be released from detention if the interests of justice permit”. A court cannot withhold bail to punish the accused, or to demonstrate disapproval of the alleged crime. To do this would “amount to a form of detention without trial, which was widely used in the Apartheid era against political opponents of the National Party regime”. If Pistorius is denied bail, he could also spend months, if not years, in prison while awaiting trial – also reminiscent of Apartheid.

The defence must show that Pistorius is not a flight risk, is not a danger to the public, and would not jeopardise the investigation into the crime he is accused of committing for bail to be granted.

But the defence’s task was further complicated when the magistrate ruled that the bail hearings would proceed on the basis that Pistorius should be charged with a “Schedule 6” premeditated murder. This carries a minimum life sentence and puts the onus on the defence to establish “exceptional circumstances” which allow the court to release him pending trial – prompting both sides to provide more detailed evidence and argument sooner than they had initially intended.